[42.01] Photometric Evolution of the Deep Impact Flash

C. M. Ernst, P. H. Schultz (Brown University), Deep Impact Team

On July 4, 2005, the Deep Impact mission performed a
planetary-scale impact experiment into comet 9P/Tempel 1.
The 10.2 km/s impact was energetic enough to produce radiant
energy observable in the visible wavelengths. We will report
on the characteristics and photometric evolution of the
first moments after impact as observed by the flyby
spacecraft. The observations will be compared to
extrapolations of impact flash measurements made during
hypervelocity impact experiments performed at the NASA Ames
Vertical Gun Range. These experiments indicate that
0.01-0.1% of the impact kinetic energy goes into the
visible light output. Analysis of the light output for Deep
Impact will help to constrain the physical state and nature
of the impacted cometary surface.